title: Effects of nifedipine on left ventricular diastolic function in patients with asymptomatic or minimally symptomatic hypertrophic cardiomyopathy.
abstract: We investigated the effects of nifedipine on left ventricular diastolic function in 17 asymptomatic or minimally symptomatic patients with hypertrophic cardiomyopathy by simultaneously measuring left ventricular pressure and volume with a catheter-tipped manometer and biplane cineangiography. Studies were performed before and 20 minutes after sublingual administration of nifedipine (20 mg). Heart rates were held constant (79 +/- 12 beats/min, mean +/- SD) by right atrial pacing. Left ventricular volumes and instantaneous rates of left ventricular volume were derived from frame-by-frame (20-msec) analyses of left ventricular biplane angiograms. Left ventricular peak systolic pressure (from 122 +/- 21 to 108 +/- 13 mm Hg, p less than 0.01 vs. control) and mean aortic pressure (from 96 +/- 15 to 87 +/- 11 mm Hg, p less than 0.01) decreased significantly with nifedipine. With afterload reduction, left ventricular ejection fraction (from 0.69 +/- 0.12 to 0.74 +/- 0.08, p less than 0.01) and cardiac output (from 6.4 +/- 2.0 to 7.2 +/- 2.2 l/mm, p less than 0.05) increased significantly. However, there was a slight but significant increase in left ventricular end-diastolic pressure (from 15 +/- 8 to 18 +/- 8 mm Hg, p less than 0.05). Nifedipine did not improve left ventricular relaxation as assessed by the time constants of isovolumic pressure decay (t1/2, from 39.8 +/- 6.6 to 39.4 +/- 7.7 msec, NS; t1/e, from 53.8 +/- 9.0 to 54.4 +/- 10.7 msec, NS).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: First Department of Internal Medicine, Mie University, Tsu, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamakado
authors.forename: H
authors.initials: H
authors.lastname: Okano
authors.forename: S
authors.initials: S
authors.lastname: Higashiyama
authors.forename: M
authors.initials: M
authors.lastname: Hamada
authors.forename: T
authors.initials: T
authors.lastname: Nakano
authors.forename: H
authors.initials: H
authors.lastname: Takezawa
mesh_terms: D002304:Cardiac Pacing, Artificial; D002312:Cardiomyopathy, Hypertrophic / Q000188:drug therapy* / Q000503:physiopathology; D002932:Cineangiography; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects*; D009543:Nifedipine / Q000494:pharmacology*; D013318:Stroke Volume / Q000187:drug effects
chemical_list: D009543:Nifedipine